Figure 2
Compilation of images of diagenetic aragonite encrustations. (a) Aragonite encrustations occurring in high density within the Ahlat Ridge composite profile sediment (5034_2_E_11H_1, 49.3 to 53.7 cm depth), visible to the naked eye as speckled dots in high resolution core images (ICDP sampling party). Note the abrupt transition between an abundance of aragonite encrustations in the lower part of the section and their absence in the upper part. (b) Digital stereomicroscope photograph depicting a part of the sieved > 250 µm fraction from (5034_2_E_11H_1, 54 to 56 cm depth). The image taken using the image software ZEN 2.3 lite (https://www.zeiss.de/mikroskopie/produkte/mikroskopsoftware/zen-lite/zen-lite-download.html). Note the abundance of encrusted ostracod valves of which many are still articulated. (c) External lateral view of a partly encrusted ostracod valve missing the typical reticulation on the valve visible on well preserved Limnocytherinae valves typical for this depth in Lake Van (52.087 mcblf). (d–f) Articulated encrusted ostracod valves showing various stages of carapace opening. g) Tubular encrustation around a still encapsulated unidentified biological remain. (h) Partly encrusted biological remain. (i) hollow encrusted cast structure with missing original substrate on which aragonite precipitated. The yellow area is magnified in (l). (j) Articulated ostracod valves with a smaller carapace stacked inside. The red area is magnified in (k). (k) Magnification showing larger aragonite crystals growing in the hollow area between valve and encrustation. (l) Magnification showing small aragonite crystals intercalated with clay minerals in the surface of an encrusted tube (i). (m) Large euhedral aragonite crystals precipitated within a previously enclosed carapace. Blue area is magnified in (n). (n) Magnification of the prismatic aragonite crystals from (m).
